ML20028A630
| ML20028A630 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 11/10/1982 |
| From: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20028A631 | List: |
| References | |
| FYR-82-109, NUDOCS 8211240034 | |
| Download: ML20028A630 (2) | |
Text
r Telephorts (617) 872 G100 s
TWX 7103807G19 YANKEE ATOMIC ELECTRIC COMPANY
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1671 Worcester Road. Framingham Massachusetts 01701 FYR 82-109 N,'T/\\hJ FC EE November 10, 1982
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. United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Mr. Dennis M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing
References:
(a) License No. DPR-3 (Docket No. 50-29)
(b) YAEC Letter to USNRC, dated September 28, 1982 (FYR 82-95)
(c) USNRC Letter to YAEC, dated July 22, 1981
Subject:
Revision to Cycle XVI Core Performance Analysis - YAEC-1325
Dear Sir:
As a result of our review of the Cycle XVI Core Performance Analysi:
YAEC-1325 [ Reference (b)], the values for initial boron concentrations in Modes 1-6 were found to be in error; however, the conclusions from our analysis remain valid. The purpose of this letter is to provide the corrected values and discuss the impact of these changes.
Revised pages to YAEC-1325 are attached. Also, a typographical error was corrected on Page 70 and is attached.
The revised values for boron concentration have been corrected to account for the fuel temperature reactivity effect previously neglected in the original calculation.
An evaluation has been conducted to determine the impact on the Cycle XVI Core Performance Analysis. The only transierat that could be affected by the revised boron concentrations is the boron dilution incident. For all modes, the minimum time to loss of shutdown margin was re-calculated to verify that the values approved for the reference analysis SER [ Reference (c)) were still bounding for the current reload. Use of the revised boron concentrations still demonstrates significant margin to the reference analysis as summarized below:
Time to Loss of Shutdown Margin (minutes)
[)()l Reference NRC Mode Previous Revised Analysis Criteria l
1 47.3 48.6 46.2 15 2
47.3 48.6 46.2 15 3
33.5 33.5 32.7 15 4
25.4 25.1 21.1 15 5
25.4 25.1 21.1 15 6
38.2 35.2 21.5 30 8211240034 821110 PDR ADOCK 05000029 P
PDR j
- United States Nuclear Regulatory Commission November 10, 1982 Attention:
Mr. Dennis M. Crutchfield Page 2 Based on these results, the conclusions of the Cycle XVI Core Performance Analysis are not affected:
that for boron dilutions initiated during any operational mode, adequate time exists for the operator to determine the cause of the dilution and take corrective action before a complete loss of shutdown margin occurs.
It should be noted that the analysis for Modes 1 and 2 take credit for more shutdown margin than the analysis 'in Reference (b). However, as noted on the attached page 65, the value used (5.0%Af versus the previous 4.72%Af) is still conservative with regard to the proposed Core XVI Technical Specifications.
We trust this information is satisfactory: As with the Cycle XVI Core Performance Analysis, this revised information has been reviewed by the NSAR Committee. If you have any questions, please contact us.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY J. A. Kay Senior Engineer - Licensing JAK/dd
.